This study investigates the fatigue and healing performance of asphalt mixtures incorporating nanoparticle-modified binders, using nanoclay and nanosilica. Two binders (PG 58-28 and PG 76-22) were selected to assess their effect on healing behavior. Asphalt mixtures were prepared using granite aggregates and UFGS Gradation 3, then subjected to mechanical and simulation-based evaluations. Cyclic fatigue testing was conducted using the asphalt mixture performance tester at 25°C, with a strain amplitude of 800 microstrains and a loading frequency of 10 Hz. To simulate in-service conditions, 10- and 20-minute rest periods were introduced after 25% of the specimen’s estimated fatigue life, representing early stage fatigue damage accumulation. Healing was quantified by comparing the number of cycles to failure (N f ) before and after rest period. Dynamic modulus testing and FlexPAVE™ simulations were also performed to assess viscoelastic behavior and long-term pavement performance. Results showed that both nanoclay and nanosilica modified mixtures exhibited notable improvements in fatigue life relative to the control, with nanoclay modified mixtures achieving the highest fatigue life improvement, while nanosilica modified mixtures demonstrated consistent intermediate gains across both binder types. FlexPAVE™ simulations indicated a 37% reduction in total fatigue damage over 20 years for nanoclay-modified mixtures with rest periods. Rutting and cracking resistance also improved significantly, as observed from indirect tensile asphalt cracking test and asphalt pavement analyzer tests. The findings confirm that nanomodification, especially with nanoclay, enhances the intrinsic healing capacity, fatigue resistance, and durability of asphalt mixtures. Incorporating rest periods in design further optimizes long-term performance, offering a sustainable strategy for modern pavement systems.
Mensah et al. (Sat,) studied this question.